Furnace-grate.



No. 685,7l8. Patented Oct. 29, |901. W. M. GREEN & J. R. GENT.

FunNAcE GRATE.

(Application med Apr, 4. 1900.) (N0 Model- 4 Sheets-Sheet l.

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No. 685,7la. A Patented ont. 29, |901. w. M. GREEN E J. R. GENT.

FURNACE GRAT'E.

(Application med Apr. 4, 1900.) (No Mudel.) 4 Sheets-Sheet 2.

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No. 685,7ls. Patented. mp2s, |9ol. w. M. GREEN & J. R. GENT.

FUBNACE GRATE.

(Application vfxled Apr. 4, 1900.]

ms mams PUERS co, mom-urna. WASHINGTON. l?, c,

No. 685,7I8. Patented 0st. 29,1901.

` w. M. GREEN 8. J. R. GENT.

FuRNAcE GRATE.

(Application filed Apr. 4 1900.) v (No Model.) 4 sheets-sheet 4.

TN.: nonms Vanns co. immuun- 0., WASHINGTON u c UNITED' STATES 'PATENTOFFICE.

WILLIAM M. GREEN, ornvANsroN, ANnJoHN R. GENT', or cIIIoAGo, ILLI- jNors, AssIeNoRs To JOSEPH F. GENT, or INDIANAPOLIS, INDIANA.

FuRNAcE-GRATE.

srEcIrIcATIoN ,forming part of Letters Patent No. 685,718, dated otober29, 1901. Application filed April 4, 1900. Serial No. 11,441. (Nomodel.)

^ I3 eling or endless-belt grate'by which the fuel is delivered at thefeed-opening of the furnace and is continuously fed forward or advancedwhile combustion is taking place,van'd more especially to traveling orendless-belt zo grates of that class in which the endless belt formingthe grate is a chain belt made or built up of a plurality of shortlongitudinally-4 arranged grate bars, which constitute the links of thechain belt and are pivotally connected with each other by transversepivotrods, which engage the overlapping ends of said grate-bars and inwhich the grate ismounted in a movable frame, which may be removed fromand inserted into'its place in 3o the furnace. i

The invention consistsv in the matters hereinafter described, andpointed out in the appended claims.

In the accompanying drawings, illustrating our invention, Figure l :is asectional elevation showing a boiler-furnace and traveling grate, takenon a plane parallel with the front wall of the furnace and illustratingthe grate and its supporting-frame. Fig. 2 isa view in 4o` sideelevation of the grate and its frame.

Fig. 3 is a plan view of the supporting-frame of the grate with partsmounted thereon, together with a portion of the grate proper. Fig. 4 isa detail plan view of the grate-supporting frame and parts connectedtherewith at the rear end of the same. Fig. 5 is a detail section takenon line 5 5 of Fig. 4. Fig. 6 is a detail section through the links orgratebars of the grate, showing in cross-sectional 5o view thepivot-rods connecting the same, this section being taken on line 6 G ofFig. 5.

Fig. 7 is a View in lside .elevation of one ofl the grate-bars adjacentto the side margin of the grate. Fig. Sis adetail section taken on thehorizontal line 8 8 of Fig. 2. 55

The grate illustrated is mounted on a mov- 6o I able frame, which issupported on wheels and is adapted for insertion into the furnace orremoval from the same. The supportingrails on which the frame of thegrate is supported are indicated in the drawings by ct a, saidsupporting-rails being, as shown, mounted on the side walls A A and atthe lower parts of recesses formed in said side walls to receive thesides of the frame and grate. Said frame is formed by means of twolongitudi- 7o nal side pieces E, cross-girths E' E2, which eX- tendbetween and are attached at their ends to the side pieces, and alongitudinal framevpiece or girth E3, arranged atY the longitudiarehollow or tubular in form and provided 8o "with Hanges at their ends, bywhich they are attached by bolts to the inner faces of the side pieces.The central longitudinal frame- 'piece E3 is shown as similarly made oftubular form and flanged at its ends for attachment by bolts to theinner faces of thecrossgirths E/ E2. The frame is provided withsupporting-wheels e e, arranged at each end of the frame and mounted independing bearinglugs e,projecting below the lower edges of the 9o sidepieces E E. Mounted on the said carriage,

at the front end thereof, is a horizontally-ar` ranged sprocket-wheelshaft F, carrying a plurality'of sprocket-wheels F, and at the rear endof said carriage is a similar sprocketwheel shaft G,carrying a pluralityof sprocketwheels G. The chain grate is supported at its ends on saidsprocket-wheels F G and is moved or driven by these at the frontend ofAthe frame. Said chain grate consisis of a 10o plurality ofrelativelyshort grate-bars,which extend longitudinally of the grate andare pivotally connected with each other to form a chain or endless belt,said bars being called link-bars. The grate illustrated is formed bymeans of two kinds or sets of said linkbars, of which those marked H areadapted to engage the several sprocket-wheels E' G and may be calleddriving link-bars, while those marked I constitute the greater part ofthe fuel-supporting surface of the grate and are located between thedriving link-bars H H. The grate is, moreover, divided into a pluralityof sections or separate belts or bands, that herein illustratedconsisting of two such belts or bands, (indicated in the drawings by theletters J J The several link-bars of each grate-section arepivotallyjoined or connected by means of pivot bars or rods K, whichextend transverselyof the link-bars and pass through the overlappingends of the series of link-bars on either side of the same and are madeof flattened form. Each belt or section is provided with several sets ofdriving link-bars H, corresponding with the sprocket-wheels in numberand location. I'n the case of the driving link-bars the said pivot-rodspass through eyes 7L therein, said eyes consisting each of a circularpart, through which the pivot-rod K passes, and a slot or opening h',which opens through the bottom edge of the link-bar into the aperture hand is made considerably narrower than the diameter of said aperture,but of suitable width to permit the passage through it of the flattenedpivot-rods 'in disconnecting the bars from said rods. Surrounding thesaid bearing-aperture 7L are hubs or flanges H', which meet or rest incontact with each other when the bars are placed together in overlappingrelation. Said eyes, moreover, are made larger in diameter than thewidth of the pivot-rods, and cylindric bearing-blocks h2 are inserted inthe eyes h and are slotted for the insertion of the pivotrods. Thevertical parts or webs of said driving link-bars H H are located at aproper distance apart to leave a space between them sufficient in widthto receive the teeth of the sprocket-wheels F G, and the hubs H on saidbars are made of such length as to meet midway between the webs of thebars and to form bearing-surfaces, which enter between the teeth of thesprocket-wheel and are engaged by such teeth in the actuation of thechain.

The link-bars I, which iill the spaces between the driving link-bars H,are provided with apertures like those in said link-bars H, the samehaving main parts t', of circular form, and slots i', leading from thelower edges of the link-bars into said slots or eyes. Said slots aremade of proper width to receive the attened pivot-rods and the eyes of adiameter equal to the width of the pivot-rods, so that the latter mayturn in said eyes while remaining constantly in bearing engagement withthe links. The link-bars are removed from the pivot-rods by turning thesame into a vertical position, so that they will pass through the slotsin the pivot-bars as the latter are lifted from engagement with saidpivotbars in the same manner as set forth in our prior patent, No.637,108, dated November 14, 1899.

In order to hold the pivot-bars in angular position, and thereby preventtheir withdrawal through said slots or openings in the usual operationofthe grate, a set of marginal link-bars L is provided, said marginalbars being located outside of the driving link-bars H at each side oteach grate-section and having in place of eyes or circular openings toreceive the pivot-bars two oblique slots l Z, Fig. 7, into which theends of the link-bars may be inserted after the link-bars have beenengaged with the pivot-bars and the latter have been turned or rotatedinto an angular position to prevent disengagement of the linkbarstherefrom. When the pivot-bars are engaged with the said external ormarginal linkbars L L, as described, they will be held from rotation andcan onlyvbe turned to a position with their flat sides vertical topermit the removal of one of the link-bars by disconnecting the saidmarginal link-bar L from the ends of two adjacent pivot-rods. Forholding the marginal link-bars in place upon the pivot-bars and at thesame time holding the pivot-bars from endwise movement any suitablefastening devices may be applied to the ends of the pivot-bars, thoseherein shown consisting of Cotter-pins Z', inserted through the ends ofthe pivot-bars which project outwardly beyond said link-bars L.

At the middle of the grate the marginal bars L L on the adjacent edgesof the gratesections are arranged close together, so as to leave only anarrow space between the same not materially wider than the spacebetween the other link-bars forming the supportingsurface of the grate.

The sprocket-wheel shaft F, at the front end of the grate, is mounted atits ends in bearings ff, formed in plates or castings E, which arebolted to the outer faces of the side pieces E E, which project forwardof the cross-girth E. A third bearing f' for said sprocket-wheel shaftis provided at the middle of the grate, the same being formed in abracket E4, which is bolted to the cross-girth E' and extends forwardlytherefrom.. Similarly the rear sprocket wheel shaft G is mounted at itsends in bearings g g, mounted in plates or castings E7, bolted to theouter faces of the rear ends of the side pieces E E, and said shaft G issupported at its middle ina third bearing g', mounted on a bracket E5,which projects rearwardly from the rear cross-girth E2 of the frame. Asherein shown and preferably constructed, the lugs e e', which att'ordbearings for the supportingwheels e e, have the form of downwardintegral projeetions on the lower edges of the said plates Eb' and E7.

The sprocket-wheels F/ and G are arranged one at each end of the shaftsF G in position IOC) to engage the driving-links H H at the outermargins of each grate-section, and two of said sprocket-wheels arelocated on said shafts E and G at either side of the central bearings f'g', so as to engage the driving-links H H,

which are located at the inner or. adjacent margins of said sections.Other sprocketwheels are located between the sprocketwheels, whichengage the driving link-bars at the side margins of the sections, saidintermediate sprocket-wheels being adapted for engagement withintermediate sets of driving link-bars. Each lateral half or section ofthe grate is shown in the instance illustrated as provided at each endwith two intermediate sprocket-wheels, and the grate-sections areprovided with corresponding sets of driving link bars. By employing aplurality of sprocket-wheels on each lateral half `of the forward ordriving shaft F, together with a plurality of sets of driving link-barsin each of the chain-sections, the pivot-rods are relieved of the strainwhich would be brought thereon by reason of the lagging or pulling backof the parts of the belt if the grate-sections were driven solelythrough their marginal driving link-bars, it being obvious that so faras the advance movement of the belt is concerned in the constructionherein shown the pivot-rods will be required to move or carry forwardthose link-bars only which are located between the closely-spaced setsof driving link-bars.

For the purpose of supporting or sustaining the horizontal parts or runsof the grate between the sprocket-wheels the frame or carriage isprovided with a plurality of transverse horizontally-arranged shafts MM', provided with bearing-rollers m m', of which the shafts M arelocated beneath the upper part or run of the belt and those M' arelocated below the lower part or run of the belt. The shafts M at the topof the carriage are mounted at their ends in bearings m2 m2, bolted tothe top edge of the side frame-pieces E, and at their middle parts areengaged with bearings m5, bolted tothe upper surface ofthe centrallongitudinal frame-girths E5. In the case of the shaft M nearest thefront of the grateframe the bearing m5 is bolted to the top surfaces ofthe brackets E4, while in the case of the shaft M nearest the rear ofthe frame a bearing is provided for the center of the shaft by means ofa raised longitudinal flange e2, Figs. 3,4, and 5, on the bracket E5,which flange is provided with a notch or seat e5, in which the shaftrests. The lower set of shafts M' are mounted at their ends in bearingsm4 'm4, bolted to the lower edges of the side framepieces E E,tl1eseshafts being without any central supporting-bearings.

The forward sprocket-wheel shaft is immovable with respect to the frame,the bearings fftherefor being shown as formed half in the plates andhalf in caps bolted thereto in a familiar manner. The central bearing f'is similarly formed by a recess in and a cap attached to the bracket E4.In the case of the rear sprocket-wheel shaft G, the bearings g g'thereof have the form of sliding bearings or boxes which engagelongitudinal horizontallyarranged guides e4 e4 e5, formed on the rearends of the plates E7 and on the bracket E5,

said bearing-boxes being arranged to slide,

horizontally in order that the said shaft G may begshifted backward orforward to adj ust the tension of or tighten the chain-grate whennecessary. Meansforadjustingthesaidbearings are provided as follows: Thebearings for the ends of said shaft G are adjusted by means ofscrew-shafts N N, which are inserted through longitudinal passages inthe said plates E and bear at their rear ends against said boxes, saidscrew-shafts being engaged with nuts n n, which are square or flat-sidedand are seated in fiat-sided recesses e6, formed in the vertical rearfaces of the said plates E7. Said screw-shafts are provided at theirforward ends with flat-sided portions to receive a wrench or likeimplement by which they may be turned. In the case of the centralbearing g', which is mounted to slide upon the bracket E5, as clearlyshown in Figs. 4 and 5, a special provision is made for moving thebearing E5, the same consisting of a horizoutally arranged screwshaftN', having screw-threaded engagement with a nut n', seated in a recesse7 in the said bracket and bearing at its rear end against the bearingg'. The rear cross-girth E2 is, as before stated, hollow or tubular inform, and the screw-shaft N' is extended iutothe hollow interior of thesaid girth. Mounted on said shaft N' within the said girth is agear-pinion O, which is engaged with said shaft by means of a spline orfeather engaging the groove inthe shaft, so that the shaft will turnwith the pinion, but will lslide or move endwise through the said pinionwhen the shaft is moved or adjusted by being turned in thescrew-threaded nut in the bracket E5. Mounted longitudinally in saidgirth E2 is a shaft P, having at its inner end a gear-pinion P', whichintermeshes with the gear-pinion O on the shaft N'. The outer end ofsaid shaft P is flat-sided and projects through an opening in the sideplate E of the frame, so that a wrench or the like instrument may beeasily applied to said shaft for the purpose of turning the same. Theconstruction described obviously enables the central bearing g' to beadjusted from one side of the grate. When the shaft P is turned, theshaft N' will be correspondingly turned or rotated, thereby moving itendwise against the bearing g'. By adjusting the three screwshafts N Nand N' the shaft-bearings may be moved backwardly any extent necessaryfor the proper adjustment of the tension on the chain-grate. By theemployment of the nuts n n', seated in recesses in the plates E7 andbracket E5, as described, the construction of the adjusting devices isgreatly simplified and the cost thereof decreased, the necessity ofproviding a screw-threaded aperture in IOO IIO

.said forward shaft.

the large castings E7 and bracket E5 being avoided.

All of the sprocket-wheels G but one on the rear shaft Gr are loose onthe shaft, so as to turn freely thereon, one only of said wheels beingafiixed to the shaft, so that the latter will be turned in its bearingswith the several sprocket-wheels. This construction insures that thesaid sprocket-wheels engaged with the two grate-sections or withdifferent parts of the same grate-section will remain properly inengagement with the grate notwithstanding any inequalitiesin the drivinglink-bars or lagging of one belt behind the other or one part of one ofthe belts with regard to other parts thereof. To hold the saidsprocketwheels G' from endwise movement on the shaft F, collars g2 areshown as secured to the shaft on opposite sides of the hubs of eachsprocket-wheel.

The driving sprocket-wheel shaft F will always be made continuous; butthe shaft G need not be continuous, but may consist of two or moreseparate parts or sections. It is preferred, however, that onesprocket-wheel on the shaft G, or on each section thereof if the sameconsists of more than one section, be rigidly secured to the shaft, andthereby cause the shaft to revolve, so as to avoid the friction whichwould be due to the turning of the said sprocket-wheels on the shaft, itbeing obvious that the loose sprocket-wheels will not turn on the shaft,but will be merely shifted slightly thereon as required byirregularities in the parts of the belt or in the movement of thedriving link-bars thereof.

It will of course be understood that anysuitable driving means maybeemployed to give motion to the forward sprocket-wheel shaft for drivingthe grate, it being thought unnecessary to illustrate such driving meansin connection with the present invention, as they constitute no part ofthe same.

An important part of this invention is included in the constructionembracing in connection with a single wide supporting-frame a continuoussprocket-wheel shaft at the front of the frame, which is driven to givemotion to the grate', and a sprocket-wheel shaft at the rear of theframe, the sprocket-wheels on which are adapted to turn or moverelatively to each other, of a belt or chain grate dividedlongitudinally into a plurality of parts or sections and which areengaged by the sprocketwheels on the said sprocket-wheel shafts, saidbelt being driven through the turning of the The advantage of thisconstruction is that a grate is thereby provided which may be much widerthan would be practicablefor use if the grate were made continuous fromside to side of the same and which will operate properly andsatisfactorily notwithstanding irregularities in the driving link-barsand yielding of the shaft to which power is applied under the torsionalstrain on the said shaft. If the belt be wide and in one piece, suchyielding of the driving-shaft under strain usually results in one partof the belt dragging or lagging behind the other, with the effect ofbending or throwing into oblique positions the several pivot rods,thereby causing the parts to bind and preventing the proper operation ofthe grate. When the belt is made of two or more sections and thesprocket-wheels on the rear shaft are free to turn relatively to eachother, as herein illustrated and described, the fact that one part orsection lags behind the other by reason of such torsional strain onoryielding of the driving-shaft will make no difference in the operationof the grate, as each part or section will move independently andwithout interference with the action of the other part or parts. Theimportance of this feature of the invention will be better understoodupon consideration of the fact that when the grate is carrying its loadof fuel a very considerable amount of poweris required to move the same,and if for the purpose of transmitting such power through a singledriving-shaft said shaft were made heavy and strong enough to preventany substantial yielding of the same under torsional strains it wouldneed to be .so large and heavy as to involve large expense in itsconstruction and much trouble in handling it, especially in cases wherethe shaft is very long, as is the case in a wide grate such as is hereinshown. By the use of the construction herein described, however, thegrate may be very wide and the sprocketwheel shaft very long, and at thesame time such yielding or torsional movement which may take place insaid shaft will be immaterial because having no effect upon theoperation of the grate. In a very wide grate, moreover, the diiiicultiesin the Way of smooth running of the belt due to irregularities in thedriving link-bars are greatly magnified, it being very difiicult toconstruct a device of this kind so accurately that a large number ofsets of driving link-bars and their associated sprocket-Wheels willaccurately fit or intermesh, and these diiiculties are entirely obviatedby our improvements, as herein described.

Anotherim portant feature of our invention is embraced in theconstruction in the gratesupporting frame by which the same isespecially adapted for use in connection with wide grates having aplurality of grate-bar sections. It is found that the frame made up, asherein shown, of longitudinal pieces, transverse girths of tubular formconnecting the same, and a central longitudinal girth which serves torigidly connect the centers of the cross-girths and also to affordsupports for the centers of the supporting-roll shafts, affords in highdegree the necessary qualities of rigidity and strength combined witheconomy of construction.

The marginal iink-bars described, which serve both as fuel-supportingbars and also as means for locking the pivot-rods from turning, alsoconstitute a novel feature which is IIO herein claimed as a part of ourinvention. By their lateral projections from the adjacent margins of anytwo sections they bridge over the space which would otherwise exist beftween the sections and, as before described,

approach each other so closely at their outer or contiguous edges as topresent a practically continuous supporting-surface for the fuel.Consequently there is no clogging of the parts by cinders and no deadzones, but a clear even fire is maintained through the entire surface ofthe grate. At the outer edges of the sides of the grate moving supportis given also to the fuel clear up the regrate, the upper surface of themoving Inarginal grate-bars projecting under the firelining in a recessformed therein, so that the usual clogging in the corners of the furnacelire-box is prevented.

We claim as our invent-ion-` 1. The combination with an endlesstraveling grate and shafts carrying sprocket-wheels for supporting saidgrate', of Aa frame having Wheels, of an endless traveling gratesupported on said sprocket-wheels and consisting of a plurality ofseparate sections arranged side by side with their adjacent edges closetogether, each of said sections consisting of linked bars each providedwith a fuel-supporting surface and with two bearing-apertures which openthrough the lower margin of the link-bar, and a plurality of pivot-rods;the side or-margin link-bars of the grate being provided `withfuel-supporting surfaces and having each two oblique slots which areengaged with the pivot-rods to hold'the same from turning, securingmeans applied to the said ends of the pivot-rods outside of the saidmarginal link-bars, said marginal link-bars having at their uppersurfaces laterally-projecting flanges which extendover the ends of thepivot-rods and securing devices thereon and which, in the case of themarginal linkbars on lthe adjacent edges of the grate-sections, arelocated close together to form a continuous bearing-surface for theifuelbetween the side linings of the furnaces.

In testimony that we claim the foregoing as our invention We affix oursignatures, in presi ence of two witnesses, this'23d day of March, A. D.1900. v

WILLIAM M. GREEN. JOHN R. GENT.

Witnesses:

C. CLARENCE POOLE, C. W. HILLS.

